Ice-shelf buttressing and the stability of marine ice sheets
Ice-shelf buttressing and the stability of marine ice sheets
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DOI：
10.5194/tc-7-647-2013
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发表时间：
2013-01-01
期刊：
影响因子：
5.2
通讯作者：
Gudmundsson, G. H.
中科院分区：
文献类型：
--
作者：
Gudmundsson, G. H.
数值研究了冰架支撑和海洋型冰盖的稳定性。扶壁效应进行了分析的情况下，一个稳定的接地线是位于一个床向上倾斜的流动方向。这样的接地线位置在没有横向气流变化的情况下是无条件不稳定的。结果表明，冰架扶壁可以在这些条件下恢复稳定性。接地线处的冰通量一般不是冰厚的单调递增函数。这一点，起初可能有点违反直觉的结果，被发现是完全符合最近的理论工作。接地线的逆行斜坡是有条件的稳定，稳定制度是一个非平凡的功能的床和冰架的几何形状。接地线的稳定性不能仅从局部河床坡度的考虑来评估。
Ice-shelf buttressing and the stability of marine-type ice sheets are investigated numerically. Buttressing effects are analysed for a situation where a stable grounding line is located on a bed sloping upwards in the direction of flow. Such grounding-line positions are known to be unconditionally unstable in the absence of transverse flow variations. It is shown that ice-shelf buttressing can restore stability under these conditions. Ice flux at the grounding line is, in general, not a monotonically increasing function of ice thickness. This, possibly at first somewhat counterintuitive result, is found to be fully consistent with recent theoretical work. Grounding lines on retrograde slopes are conditionally stable, and the stability regime is a non-trivial function of bed and ice-shelf geometry. The stability of grounding lines cannot be assessed from considerations of local bed slope only.